Stoker construction



Dec. 28 1926.

R. A. FORESMAN STOKER CONSTRUCTION Filed April 9. 1923 2 Sheets-Sheet l dlaredmalz INVENToR ATTORNEY Dec. 28 1926. 1,612,624

. R.A A. FORESMAN v STOKER CONSTRUCTION Filed April 9. 192s 2 sheets-sheet 2 (0 I 40 Z/lreiman NTOR ATTORNEY Patented Dec. 278, 1926.

UNITE-o STATES ROBERT A. FORESMAN, F MOORES, PENNSYLVANIA, 'ASSIGNOR T0 WETINGHOUSE ELECTRIG D MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

smoxnn coNsTRoTIoN.

'ppncation inea April 9, 192s. serial No. 630,986., S

feeding retorts are alternately arranged in parallel. relation and vinclined downwardly from the front toward the rear of the furnace, for a more complete combustion of fuel at the lower end of the underfeed Stoker grate. A still further object of my inven-` tion is to provide in a multiple retort un- 'derfeed Stoker furnace a retort which shall he of generally decreasing depth from front to rear and which shall have the rear portion of the retort bottom composed of one or more tuyre plates or members.

0 f rllhese and other objects.` which are more manifest inl the further description of my invention, may be .attained by the employment of the apparatus illustrated in the accompanying drawings, in which Fig. `1 is a view in-longitudinal sect-ion of a portion of an underfeed Stoker grate embodying my invention; Figs. 2 and 3 are fragmentary views in transverse section of the apparatus illustrated in Fig. 1, taken on the lines H-H and 11F-HI, respectively, of that figure; Fig. 4 is a fragmentary plan view of the rear of the underfeed grate; Fig. 5

is a fragmentary view in elevation of the rear end of the underfeedgrate: Fig. 6 is a fragmentary view in section through the lower end of the tuyere bank; and Fig. 7 is a fragmentary view in Section of a modied form of the lower end of the retort shown in Fig. 1. Y p

Referring to the drawing for a detailed description of the embodiment of my inven; tion herein illustrated, I show an underfeed Stoker having inclined banks of tuyres 10and alternately disposed retorts 11. Ram boxes 13 are disposed at the forward ends 'of the retorts in such manner that fuel from hoppers 14 is fed into theseveral retorts 11 by reciprocating 'rams 15. refuse-discharging mechanism 16 is pro- A suitable vided at the rear of the` grate and, may Ibe in the form of an oscillating air-feeding grate, as shown. The above described structures are conventional in vstokers of the multiple retort type and since the specific structures of the feeding and'discharging mechanism form no part of the present invention,

a detailed description thereof is deemed. un-

necessary for the purposes of the present application. It is to be understood, furthermore, that other specific feeding and discharging mechanisms may be employed with the apparatus of he present invention.

Each of the retorts 1.1 consists of two angle irons 12 secured atthe rear and lower ends to`1 a member 14 which in turn is Secured to an I-beam 15, and carried at their upper ends in slots 16 of a member 17 which is bolted to an I-beam 18. Side retort plates 19 are carried by the angle irons 12 to which they are secured as by bolts 20, and are further supported by projections 14 Iof the member 14 at their lower ends, and by castings 21 disposed above and secured to the member 17 at their upper ends. .The side plates 19 are provided with'laterally extendingribs 22 which are inclined with respect to the angle irons 12 and upon which the bottom plates 23 are disposed to form re- Y torts of decreasing depth from front to rear. Side plates 19 have at ptheir upper edges flanges 24 upon which the tuyre plates 10 arearried. f

The bottom plates 23 of the retorts terminate short of the rear endscof the retorts, as shown in Fig. 1, and the bottoms of the retorts arecontinued to therear edge of the grate by means of one or more tuyre plates 25, disposed in each retort and supported on ribs 26 integrally formed in the retort side platesf19. The ribs 26 are notched, as at 27, for engagement with cooperating' lugs 28 on the tuyre plates 25. The tuyre plates 25- are similar tothe tuyre plates employed in the tuyre banks 10, with the exception that they have but a slightly curved front edge and the air discharge ports therein are designed to direct air rearwardly and horizontally through the lower. ends of the retorts into the fuel bed.- Dead plates 36 engage at their lower ends the retort sides at 31 and are carried at the rear by the front.

wall 32 of the member 14, and thus seal the face Special basetuyre blocks 36 are.

however, preferably employed at the rear or lower end of the tuyre banks. These base tuyre blocks 36 have a greater vertical dimension than the tuyre plates 35, being from two to four times vthe thickness of the tuyre plates, and are of such conformation as to resent no protruding edges which may be subjectto ready deterioration or burnin out. As shown, each tuyre block 36 has lin its upwardly resented surface a plane portion upon whlch'the lowermost tuyre plate rests and exposed sloping faces receding downwardly and rearwardly from the surface of contact of the tuyre block with the lowerniost tuyre plate 35. The rear end face of the tuyre block 36 also slopes downwardly from the rearmost edge of the tuyre plate superimposed `thereon. The base -tuyre block 36 further coacts with the r A anges 2li-of the side plates 19 and the dead tuyre openings.

The discharge mechanism 16, herein illu s'v plates 30 to anchor the tuyre bank securely 1n place at its lower end. lThebase tuyre block 36is preferably hollow and is cooled interiorly by the How of air passing to the trated, comprises an oscillating dump grate '/l0,`preferably`- sectional and in width equal cooperation with thefront'wall 32 of the to the'distance between the center lines of the tuyres,' carriedzupon a shaft `41 which is supported in brackets 42 protruding'from the rear' wall 32 of the member 14.' Air is lsupplied to the hollow grate sect-ions: 40 nthrough registering ports' 44 and from the grate to th`e residual fuel thereon through ports45.""

In'. the arrangement illustrated,the tuy're rows 10 and thebottoms of the retorts 11- voverhang-'the dump "grate (and extend frear d wardly of the side walls 19 which serve in member Ml to support these overhanging l I vtuyre banks 10 are disposed.

structures. The dead plates 30 extend the.'

width of the stoker furnace and serve as foundation. plates upon which the retort tuyres 25 a/nd the tuyres 35 and 36 ofthe operation. uhl is fed into the several retorts from theoppersv l4 by7means` of The rear, shallowj'portions of the retorts 10,

in which the retort tuyres 25 are situated, 70

are defined at the sides Aby the base tuyre blocks36. and the lower-most tuyres 35.

The' peculiar conformation o f the base tuyre blocks '36 -produces laterally expandgrate for the fuel traveling downwardly' through the retorts' and permits the air rear- .wardly discharged fromA the retort tuyres to promote more complete combustion of the rearmost portion of the fuel bed without sub 30 jecting the lower tuyres of the tuyre banks 10 to destructive heataction. I

As illustrated, the underfeed grate over# g hangs the discharge or dump grates and, by

virtue of'the cooperative action the receding 85 base t'uyre blocks 36 and the shallow retorts provided with` the retort tuyres, the resid; uum of the fuel passes to the dump grates in a substantially 'uniformlyeven bed with re'sidnum. p Experience has'thown that the underfeed stoker" hereinabove described is enabled to burn satisfactorily the large quantities of fuel necessary to supply the heat venergy load ratingat which the generating units of public utility power plantsv are frequently operated, the combustlon eiiciency of this Stoker is superior to that attained by stokers (10 having eXtended overfeed sections.v

' Inthemodified form illustrated inA Figi. I show the rear end of a retort of an un e1;-

erence numerals indicating-like parts and a/ detailed description thereof isdeemed to be unnecessary. Structures of this character ml are specially adapted to stokers of consider- 'able length and it isV to 'be understood that more than four retort tuyres may be employed 'at the esi'r'ed, This application vis a continuation-impart of my application; SeralNa 396,378, filed July 15,1920.H

lower end of the retortsivf' l iDgJtrOughs at the rearmost portions of the 75 a .minimum of uncon'sumed fuel in the to 5 boilers atl peak loads and that, at the over- 'i While I have shownl my linvention in' but in the art that vit is not s'o'limited,' but is susceptible of various other changes and modifications without departing from the spirit thereof, and I desire, therefore, that 4two forms, it willbe obvious to those skilled only such limitations shall be placed therel upon as are imposed by the prior art or as are specifically set forth'j in the appended claim.

What I `claim is:

Iman 'underfeed the reciprocating rams 15.- The fuel entering thefurnace retorts spreads' out over the -tuyre banks 1Q. and travels downwardly" jtoward the rear' of the grate.l The retorts by reason of their vdecreasing depth cause stolzer, aninclined grate l comprising a plurality of inclined banks of low end of a plurality of tuyre blocks'supertuyres and retorts between adjacent tuyre imposed one on the other in stepped relation v banks, each retort being of generally deand having tuyre openings for discharging 10 creasing depth from front to rear, the retort air rearwardly into the retort.

5 sides at the rear shallow yend of the retort In testimony whereof, Ihave'hereunto-subflaring upwardly and rearwardly, the bottom -scribed my name this 5th day of April, 1923. of each retort being formed at its rear shal- ROBERT A. FORESMAN. 

